One of the benefits over simple discussion is that there is a written record. This minimises the risk of students forgetting what was said. Students can take the post-its and include them in their own sketchbooks or they can copy them. Another advantage is that they are to the point and can even be stuck on the specific area of work they are commenting on, a detail of a painting for example.
There is also a sense of anonymity which means that less confident students are able to communicate, they may be less sure of themselves if they had to speak in front of a class. While it develops literacy and writing skills, it doesn’t feel laborious or difficult. There is the sense of immediate impact as they see so many points raised about their work in a visual way.